moderate leaf damage. The suscep- 

 tibility of sugar maple to high levels 

 of damage might be attributed to 

 the phenologies of the host and 

 pest, i.e. sugar maples are in their 

 most vulnerable stage of develop- 

 ment, bud-break, at a time when 

 adult pear thrips are most abun- 

 dant. Furthermore, fewer alterna- 

 tive hosts have reached a stage 

 susceptible to thrips attack at this 

 time, especially in many sugar 

 bushes. 



OUTBREAKS 



Insects often offend people with 

 their mere presence. It is no wonder 

 that outbreaks of insects receive 

 much attention and unnecessary 

 alarm. In the insect world, popula- 

 tion surges are usually unnoticed, 

 unless the species involved happens 

 to "bug" people. Hence, most ento- 

 mological reports on outbreaks in- 

 volve species that are categorized as 

 pests. Some eruptions of pests occur 

 in cycles and are rather easy to pre- 

 dict; others involve many variable 

 factors and can be difficult or im- 

 possible to forecast. For several eco- 

 nomically important pests, ento- 

 mologists have developed methods 

 to predict where and when insect 

 infestations might occur. For 



example, judging from the high 

 count of gypsy moth egg-masses on 

 the trees in Durham, it is evident 

 that most of the hardwood trees in 

 the vicinity of UNH's main campus 

 will be completely defoliated this 

 June, unless some preventative 

 measures are taken to decimate the 

 little munching juggernauts before 

 they eat every leaf in town. 



The thrips outbreak of 1988 

 raised several questions: Had pear 

 thrips acquired a new preference in 

 taste for sugar maples? Did this 

 situation result from the unusual 

 climatic events, or was it caused by 

 some quirk in nature? We do not 

 know why the thrips outbreak oc- 

 curred. However, we do know one 

 thing for sure, there were a heck of 

 a lot of pear thrips in the spring of 

 1988. A more important question 

 is, can we expect this type of devas- 

 tation to occur in the future? To 

 answer this question it became 

 necessary to study and observe pear 

 thrips in the field and develop a 

 method to estimate their 

 populations. 



SURVEY RESULTS 

 One of my colleagues, Craig 

 Hollingsworth, at the University of 

 Massachusetts, developed a method 



using sticky traps. He discovered 

 that the type of trap used to survey 

 for adult apple maggots could also 

 be used effectively to collect pear 

 thrips. These traps provided a quick 

 and easy method to estimate the 

 relative abundance and distribution 

 of thrips. The sticky trap sampling 

 method was adopted in a multi- 

 state survey of pear thrips supported 

 by the by USDA, CAPS (Cooper- 

 ative Agricultural Pest Survey) 

 Program, and 1 7 states in the 

 northeastern USA are presently 

 participating in this investigation. 

 Thus far, the resulting data show an 

 general decline in pear thrips since 

 1988. Many more years of research 

 are necessary, before it might be 

 fxjssible to make reliable long range 

 predictions. Nevertheless, the re- 

 cent downward trend is good news, 

 and provides an optimistic outlook 

 on the pear thrips situation, at least 

 for the present time. **■ 



]ohn Weaver is Survey Entomologist 

 for the Department of Entomology at 

 UNH, arid State Survey Coordiruitor 

 of the USDA, CAPS (Cooperative 

 Agriculture Pest Survey) Program for 

 New Hampshire. For more informa- 

 tion caU]ohn at (603) 862-1737. 



Jolly Farmer Products 



East Lempster, New Hampshire 03605 



WHOLESALE SUPPLIERS ■ WHOLESALE GROWERS 



Bark Mulch - Hemlock & Mix 

 Bagged Mulch - Cedar & Pine 

 Landscape Ties 

 Cut & Split Firewood 



We are here to fulfill your needs.... 

 Call Toll Free today! 



-^^ 



New Hampshire: 1-603-863-3311 

 New England: 1-800-537-0031 



Annual & Perennial Plugs 

 Rooted Cuttings 

 Tuberous Begonias 

 Bedding Plants 

 Potted Annuals 

 Hanging Baskets 

 Cyclamen - 



Liners, Prefinished, Finished 

 Polnsettias - 



Cuttings, Prefinished, Finished 



Nationwide: 1-800-695-8300 

 Local: 603-863-3370 



"Integrity, quality and reliable service since 1967' 



